When we use the provided Compose file to create
containers for this lab, a new network is created
to connect the VM and the containers. The
IP prefix for this network is \texttt{10.9.0.0/24},
which is specified in the \texttt{docker-compose.yml}
file. The IP address assigned to our VM is
\texttt{10.9.0.1}. We need to find the name of
the corresponding network interface on our VM, because we
need to use it in our programs.
The interface name is the concatenation of \texttt{br-}
and the ID of the network created by Docker.
When we use \texttt{ifconfig} to list network interfaces,
we will see quite a few. Look for the IP address
\texttt{10.9.0.1}.


\begin{lstlisting}
$ ifconfig
(*@\textbf{br-c93733e9f913}@*): flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet (*@\textbf{10.9.0.1}@*)  netmask 255.255.255.0  broadcast 10.9.0.255
        ...
\end{lstlisting}


Another way to get the interface name is to use the \texttt{"docker network"} command to
find out the network ID ourselves (the name of the network is \texttt{seed-net}:

\begin{lstlisting}
$ docker network ls
NETWORK ID          NAME                DRIVER              SCOPE
a82477ae4e6b        bridge              bridge              local
e99b370eb525        host                host                local
df62c6635eae        none                null                local
(*@\textbf{c93733e9f913}@*)        seed-net            bridge              local
\end{lstlisting}


